Improvement in printing-telegraphs



@YM/Z @f Witnesses. Inventor.

Timms. Reeksen UNITE-n STATES PATnNtrQrFIOE.

g T nOMAs A. IEDISON, on BOSTON, Assienoge To `JOEL n.v HILLS AND wiu. E.'

PLUMMER, OF NEWTON, MASSACHUSETTS.

IMPRoygMEm-IN PRiNTiNe-'TELEeRAPl-ls.

. Specification formingr part of Letters-Patent No. 911,527, dated June 22, 1869.

. Boston, in the county of Suii'olk and State of Massachusetts, have, invented certain lm- `provements in Electro-lvlagnetic Printing'lelegraphs, of which the fo'lliwving is a full, clear, and exact description, reference being 'had to the accompanying drawings making part of this specicatiompin which` .l

-fFigure 1 isa perspective view of my improved instrument;` Figs.`2 and 3, details;

y Figse and 5, .diagrams to be referred to.

4`This invention Yha'snfor'its'object to produce Ya simple, reliable, and inexpensive printing telegraph', which will 'require no 'attendant 'at y' the receiving-station and consists in the e1-ni ployment'of ,two electro-magnets plaeedgvithin the' same circuit-fone for rotating the type Wheel, the other for actuating the printing`- hammer-in ,conibinatinl with a polarized relay, which7 forms. an automatic switch that will instantly detect the direction ot' the current,` andbause it, when traveling ,in one direction, to pass onlythrough the. electro-,magnet of the type-wheel, an d, when reversed so asto'ftiavel in the contraryilirection", toppassfonly through the electro-magnet of the printing-hammer,

' Wl-ich'may thus be brought into operation, -to l the required impression upon the paper, by, simply reversing the current 'at the proper time, no local battery being required'at the reeciviugfstation, as all 'themechanisin is yper-'ate'll by the current from the' battery at the transmitting-Station.

` .5. nablefothers skilled in the art to understand and useIuy` invention, l' will proceed to describe the 'manner in' which i have carried Il'tlie said drawings, A represents the trame# work of the` instrument, to which is secured the'electro-Inagnet l5, which operates the typewheel G, the periphery ot' which is provided with the required letters and characters." The armature I) of the magnet l5 attahedl to a lever, c, which is pivoted at d, 'and is bifurcated sprin gage with the ratchet-wheel on opposite sides, so that each vibration of the' lever c backward or .forward will' rotate the type-wheel, which receives its supply of ink from the roll D, in a well-known manner.

E is the electro-magnet of the printing-hainmer, which latter consist of a roll, t', secured vto the outer end of alever, G, which is pivoted .at j, and carries the armature H of the magnet E. The strip of papel" upon which the messaoe is" to be printed isled orn a'reel'(not shown over the roll i, upon which it is held with a sufficient degree of friction bya Spring"- arm, l, providedwith an openvslOu-m, so as to allow the 'paper to be brought into contact with the edge of the type-wheel when the lever is4 raised against the resistance of the- 6 by the action of the electro-magnet- E'. T e strip of paper is fed forward'between .l 'the roll i Vand Spring-arm' l Aa`,i't`er each impression is nlade, sofas to produce the required Spa@ beer-@e111 the .lettera bri-means 0f a Dewi, a, which,.wl1en the lever G descends, engagesV ,with a ratchetiwheel, c', Fig. 3', secured to the roll ,whiclr. is thus rotated at the l required tinfeaits 'edges 7 being,` Toughened, so as to prevent the paperfrorn 4slipping thereon.

The course ofthe current' through the in- I strumeut, and themanner in which the iatter is operated, wiil'now lie-described, reference being had; particularly to Figs. 1,' 4, and 5:

l K are two batteries, so. arranged that but one only is employed at a time.'

Referring to Fig. 4, when the battery Iis'in use, the current passes (as indicated by black lilies and arrows) from its copper pole p,

the wire q, to the key r,- thence, 'by the wirev f J to the electro-magnet of a polarized relay", L,"

which forms an automatic switch, by means of which the course ofthe current may be changed,

aswill be hereafter particularly described, it

being, well known that the passage of a current of electricity in one direction through the electro-magnet of 'a polarized relay will causeits tongue or Ilever u to be attracted to the pOleN, and thereby l'nought into contact with the pin t, while the reversal of the current will cause it to be attracted to the pole N', Vand brought into contact with the piu "w, thereby Opening different paths for the current, so that it may be made to pass through either one oi the electro-magnets l. or lil, one ol these magnets lio. ing excluded or mit out from the circuit whihI the currcnl` is passing through the other. The construction of this polarized relay, however, being well known, and forming no part ot' my invention, will not be further described.

The instant the current passes from the wire s through the polarized relay the tongue u will be attracted by the pole N and brought into contact with the pin v, when the current will pass by the wire a: to the point 8, but as the contact is broken at u it cannot follow the wire a', and consequently passes through the elec' tro-magnet B, leaving it by the wire c', and,

instead of following this wire to the electrohh "inature b, and thereby rotating the type-wheel C, the mechanism connected with which is so arranged that the circuit requires to be closed and broken once in order to movethe wheel 0 adistance equal to that between two suc cessive letters or characters. This insures the circuit being open whenever a letter is brought into the position to allow of its impression he- 'ing taken off upon the strip of paper.

then the type-wheel has been rotated (by operating the transmitter) until the desired .letter has been brought into position beneath the roll t', the current is reversed by shiftin g the key i' into the position seen in Fig. 5, which disconnects the battery I, and causes the current om the copper pole g of the battery K to pass, by the w-ires h and j", to the groundl plate, thence to the distant ground-plate, en tering the instrument by the wire c. This re versal of the current causes the tongue u of the polarized relay to be instantly attracted to the pole N and brought into contact with the pin w, breakilig the contact at r, as seen in Fig. 5.

The action of the polarized relay is so much quicker than that of an ordinary electro-inagnet that the lever u is shifted from the point 'v to the point w before the electro-magnet has time to act, and this magnet being cut out of the circuit as soon as the tongue u comes in contact with the pin w, the current will pass,

as indicated by the red lines and arrows, Fig.

.1, hy the wires li f' c. i', to the clectro'niagnct l) ot' the printing-hammer and thence, (instead of passing through the electroinagnct B,) by the shortest course, through the wires c' d', to the tongue u, thence, by the contactpin zu and wires a/ a', to the electrounagnet of the polarized rclay, and, by the wire s, key o' and wire It', to the zinc pole of the battery K7, completing the circuit and causing the armature H to be attracted to the magnet E, raising the loyer G and bringing the paper into contact with the letter on the type-wheel, asrefqmired.v The lhey 1' is then movcdback into the position seen in Figs. 1 and 4, which again reverses 'the current and causes it to take the course iirst dcscribed, through the electro-i'nagnet B of the type-wheel, but notl through the electro-magnet E, the armature of which ceases' to be attracted when the lever G, with tlieoll i, is drawn down by the spring/6 and the paper fed forward to receive the-next impression 'as required, wlienthe operation continues as liefore. It will thus he seen that by the employment of a polarized relay, as above described, either one of the electromagucts B or E may be brought into action, and the other cut out of the circuit at pleasure by the reversal of the current, which enables me to greatly simplify the construction of' printing-telegraphs and re duce their cost. l

The above-described invention is designed particularly for transmitting intelligence from a central station toanumber of receiving stations included inthe circuit, in which case no batteries oroperators will be required. at .the receiving statious but if messages are to be sent from each station, as well.I as received, then each instrument will require to bc provided with a transmitting instrument, a battery, and an ordinary switch cimnccted with a ground-wire.

W hat I. claim as my inventiolnaiul desire to .secure hy Leiters Patent, is-

The two electro-magnets B E, placed within the saine circuit, one for operating the typewheel, thc other for operating the printing hammer, in combination with a polarized relay which forms an automatic switch, whereby either one of the electro-'magnets may be brought into action, 'and the other cut out ot'v the circuit by the reversal of the current, sub stautially as and for the purpose described.' THOMAS A. EDISON. Witnesses: P. E. TEscHEMAcHEn, W.f .li Gnrmnrocn. 

